Form tie



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FORM TIE T. C. SCHENK Filed Dec. 20, 1938 N ww gana'sCJcizenlf PatentedOct. 15, 1940 UNITED STATES FORM TIE Tamis C. Schenk,. New ,York, N. Y.,assignor' to Richmond Screw Anchor 00., Inc., Brooklyn, N. Y., acorporation of New York Application December 20, 1938, Serial No.246,831

1 Claim.

broken off by twisting, at points within the wall near the oppositefaces thereof. With such an arrangement, the broken-off end sections ofthe rod are pulled out of the wall, leaving an intermediatesection ofthe rod remaining therein. One of the difficulties generally encounteredin connection with tie rodsiof the so-called breakofi type is due to theextraordinary adherence of the concrete to the rod so that even afterthe end portions of the rod have been twisted within the concrete tosever them from the central portion of the rod, these end portions arevery difficult to pull out of the concrete due to the ad- 25 herence ofthe concrete to the parts of the ends of the rod which are in theconcrete and due also to the wedging action produced by loosenedparticles of concrete against the surfaces of the embedded portions ofthe broken-off ends of the rod.

The present invention contemplates the provision of means by which theremoval of the broken-off end portions of the rod from the concrete isgreatly facilitated; by which also the holes or openings at the oppositefaces of the concrete wall are but slightly larger than the diameter ofthe rod, and by which adherence of the concrete, or the wedging actionof particles of the same, upon the embedded portions of the broken-offends is prevented.

In the accompanying drawing, wherein an embodiment of the invention isdisclosed, Fig. 1 is a side elevation of a wall structure with the formtie in position; Fig. 2 is an enlarged sectional view of a portion ofthe tie showing one of the spacing members and one of the break-ofipoints in the tie rod; Fig. 3 is a similar section showing one of theend portions of the tie rodbroken off and the passage through thespacing member filled or pointed with concrete; and Fig. 4 is asectional view of a modified form of spacing member.

The improved tie is adapted for use with any suitable concrete formwhich may consist of the horizontally extending form boards 5,reinforced by horizontal beams 6 and uprights 1, all of which may beused to provide a form for a wall or other concrete structure in theconventional way. The form tie consists of a single section of roundmetal rod 8 preferably but not necessarily provided with short, spacedcrossbars 9 Welded or otherwise secured to the rod for the purpose ofpreventing rotation or turning of the central part III of the rod withinthe concrete structure ll 'while the end portions I2 of the rod arebeing twisted to break them off at the weakened points l3 provided inthe rod. These weakened points I3 are located relatively close to thebars 9 and adjacent to collars or stop members [4 which are preferablyintegrally formed on the rod 8.

Cylindrical spacing members [5 are utilized to hold the form boards 5 oneach side of the concrete structure I l in proper spaced relationship,each one of these spacing members consisting of a cylindrical elementloosely mounted on the rod 8 and having one end held against one of thecollars l4 by the form boards, and its other end disposed against theinner. face of the form boards.

At each end the form tie rod is provided with an enlarged head or washer20 against which a wedge 2| is employed to draw together the parts ofthe form. The pressure of the two wedges 2| holds the form parts inposition and presses the form boards 5 against the spacing members l5,holding their opposite ends against the stop collars M. The form boardsare perforated at 22 to permit the passage of the tie rod as shown inFig. 1.

Each of the spacing members I5 is provided with a centrally locatedpassage l 6 of such diameter that the rod loosely fits through it. Itwill be seen that when each spacing member is in the position shown inFig. 1, it extends over and encloses one of the weakened break-01fpoints I3 of the rod. Thus, the concrete which is poured around thecentral portion of the rod and around the spacing members 5, does notcome into contact with that portion of the rod located within thepassage IBof each of the spacing members 15 and so no concrete contactsor adheres to the portion of the rod adjacent to the weakened break-offpoints l3. After the concrete has been poured and has hardenedsuficiently, the end portions l2 of the rod 8 are twisted to cause'themto break off at the weakened points I3, leaving the central portion Illof the rod remaining embedded in'the concrete wall ll. Since the portionof the rod located within each of the spacing members I5 does not comeinto contact with the poured concrete, it may be at once pulled out ofthe passage [5 Without resistance and without requiring any particulareffort to do so.

The spacing members 15 are preferably made of a material havingcharacteristics approximating those of the concrete so that thesespacing members may remain in the wall and form a permanent part of thesame after the end portions I2 of the rod have been broken off and havehad their ends drawn out of the spacing members. The spacing members maybe made of such material as concrete, glass, porcelain, or of one ofnumerous thermo-plastic materials having the same co-efiicient ofexpansion and other characteristics as concrete such as the hardness andlasting qualities thereof, so that they will remain securely within theconcrete wall and form a permanent part of the same. After the endportions l2 of the rod have been removed, the central passage l6extending through each of the spacing members I5 may be plugged orpointed with concrete as indicated at I! in Fig. 3.

In Fig. 4 is shown a modification of the spacing member l5, the samehaving its outer surface irregularly formed, corrugated, or otherwiseribbed as shown at I8, such a surface acting to securely interlock thespacing member with the concrete poured around it. The surface of thepassage I6 extending through the spacing member l5 of Fig. 4 may besimilarly corrugated or otherwise irregularly formed as indicated at l9so that the concrete pointing plug I! will be securely anchored withinthe passage l6 after the broken-off ends of the rod 8 have been removed.

By the arrangement shown, the broken-off ends of the rod may be promptlyand speedily removed since they are not engaged by adherent concrete andthe removal of the form boards can progress with rapidity. Theutilization of spacing members of a nature permitting them to remain inthe wall and form a permanent part of the same, results in theproduction of holes or Openings in the wall only slightly larger thanthe diameter of the rods so that these holes can be easily filled 5 andeven if not filled, will not be particularly unsightly on the faces ofthe wall. The spacing members employed are preferably of non-metallicmaterial so that the same are thus non-corrosive and will not stain ordiscolor the wall, but instead will blend with the surface of the walland will, in use, be relatively unnoticeable.

What I claim is:

A form tie for concrete structures comprising a rod having a weakenedpoint at which it may be broken after being embedded in a concretestructure, a spacing member of less length than the thickness of theconcrete structure, said spacing member having a passage through whichthe rod loosely extends, means for positioning the spacing member on therod whereby the spacing member extends over and covers the weakenedpoint of the rod, the spacing member being of a non-corrosive materialhaving characteristics of expansion and contraction approximating thoseof concrete whereby it may remain embedded in the concrete structure atone of its faces but not wholly through the concrete structure to form apermanent part of the same after the rod has been broken off at theweakened point and the broken-oft end portion of the rod has beenwithdrawn from within the spacing member, the inner and outer faces ofthe spacing member being corrugated to facilitate the permanentanchorage of the spacing member within the concrete and to aid in themaintenance of concrete pointing.

material within the passage of the spacing member.

TAMIS C. SCHENK.

